Andrej Obuljen | Detection of Anisotropic Galaxy Assembly Bias in BOSS Galaxies

Parallel Talk | Cosmology from Home 2020
https://www.cosmologyfromhome.com/

Talk title:
Detection of Anisotropic Galaxy Assembly Bias in BOSS Galaxies

Talk abstract:
In this talk I will present recent evidence of anisotropic galaxy assembly bias in BOSS DR12 galaxy sample at a level exceeding 5 sigma. While galaxy assembly bias is related to scalar properties, anisotropic galaxy assembly bias is related to orientation dependent, non-scalar properties. Through the galaxy-halo alignment, non-scalar galaxy properties can be correlated with the large scale tidal fields and selections based on these properties may result in an additional anisotropy in the clustering strength. We use measurements of the line-of-sight velocity dispersion and stellar mass to perform a simple split into subsamples of galaxies. These subsamples have matching monopoles but significantly different quadrupoles of the power spectrum on all scales, manifesting different levels of clustering anisotropy. We combine data from the LOWZ and CMASS NGC samples and findIn this talk I will present recent evidence of anisotropic galaxy assembly bias in BOSS DR12 galaxy sample at a level exceeding 5 sigma. While galaxy assembly bias is related to scalar properties, anisotropic galaxy assembly bias is related to orientation dependent, non-scalar properties. Through the galaxy-halo alignment, non-scalar galaxy properties can be correlated with the large scale tidal fields and selections based on these properties may result in an additional anisotropy in the clustering strength. We use measurements of the line-of-sight velocity dispersion and stellar mass to perform a simple split into subsamples of galaxies. These subsamples have matching monopoles but significantly different quadrupoles of the power spectrum on all scales, manifesting different levels of clustering anisotropy. We combine data from the LOWZ and CMASS NGC samples and find more than 5 sigma evidence for the presence of anisotropic galaxy assembly bias on scales of k less than 0.15 h/Mpc.